From d0c05fe4448db5cbdd886186860581f736f59ae9 Mon Sep 17 00:00:00 2001 From: Gerrit Renker Date: Thu, 4 Sep 2008 07:30:19 +0200 Subject: dccp ccid-3: Simplified handling of TX states Since CCIDs are only used during the established phase of a connection, they have very little internal state; this specifically reduces to: * "no packet sent" if and only if s == 0, for the TX packet size s; * when the first packet has been sent (i.e. `s' > 0), the question is whether or not feedback has been received: - if a feedback packet is received, "feedback = yes" is set, - if the nofeedback timer expires, "feedback = no" is set. Thus the CCID only needs to remember state about whether or not feedback has been received. This is now implemented using a boolean flag, which is toggled when a feedback packet arrives or the nofeedback timer expires. Signed-off-by: Gerrit Renker --- net/dccp/ccids/ccid3.c | 41 ++++++----------------------------------- net/dccp/ccids/ccid3.h | 11 ++--------- 2 files changed, 8 insertions(+), 44 deletions(-) (limited to 'net/dccp') diff --git a/net/dccp/ccids/ccid3.c b/net/dccp/ccids/ccid3.c index f566eb76aeb2..5470a978be02 100644 --- a/net/dccp/ccids/ccid3.c +++ b/net/dccp/ccids/ccid3.c @@ -49,31 +49,6 @@ static int ccid3_debug; /* * Transmitter Half-Connection Routines */ -#ifdef CONFIG_IP_DCCP_CCID3_DEBUG -static const char *ccid3_tx_state_name(enum ccid3_hc_tx_states state) -{ - static char *ccid3_state_names[] = { - [TFRC_SSTATE_NO_SENT] = "NO_SENT", - [TFRC_SSTATE_NO_FBACK] = "NO_FBACK", - [TFRC_SSTATE_FBACK] = "FBACK", - }; - - return ccid3_state_names[state]; -} -#endif - -static void ccid3_hc_tx_set_state(struct sock *sk, - enum ccid3_hc_tx_states state) -{ - struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk); - enum ccid3_hc_tx_states oldstate = hctx->state; - - ccid3_pr_debug("%s(%p) %-8.8s -> %s\n", - dccp_role(sk), sk, ccid3_tx_state_name(oldstate), - ccid3_tx_state_name(state)); - WARN_ON(state == oldstate); - hctx->state = state; -} /* * Compute the initial sending rate X_init in the manner of RFC 3390: @@ -206,16 +181,15 @@ static void ccid3_hc_tx_no_feedback_timer(unsigned long data) goto restart_timer; } - ccid3_pr_debug("%s(%p, state=%s) - entry \n", dccp_role(sk), sk, - ccid3_tx_state_name(hctx->state)); + ccid3_pr_debug("%s(%p) entry with%s feedback\n", dccp_role(sk), sk, + hctx->feedback ? "" : "out"); /* Ignore and do not restart after leaving the established state */ if ((1 << sk->sk_state) & ~(DCCPF_OPEN | DCCPF_PARTOPEN)) goto out; /* Reset feedback state to "no feedback received" */ - if (hctx->state == TFRC_SSTATE_FBACK) - ccid3_hc_tx_set_state(sk, TFRC_SSTATE_NO_FBACK); + hctx->feedback = false; /* * Determine new allowed sending rate X as per draft rfc3448bis-00, 4.4 @@ -290,7 +264,7 @@ static int ccid3_hc_tx_send_packet(struct sock *sk, struct sk_buff *skb) if (unlikely(skb->len == 0)) return -EBADMSG; - if (hctx->state == TFRC_SSTATE_NO_SENT) { + if (hctx->s == 0) { sk_reset_timer(sk, &hctx->no_feedback_timer, (jiffies + usecs_to_jiffies(TFRC_INITIAL_TIMEOUT))); hctx->last_win_count = 0; @@ -324,8 +298,6 @@ static int ccid3_hc_tx_send_packet(struct sock *sk, struct sk_buff *skb) } ccid3_update_send_interval(hctx); - ccid3_hc_tx_set_state(sk, TFRC_SSTATE_NO_FBACK); - } else { delay = ktime_us_delta(hctx->t_nom, now); ccid3_pr_debug("delay=%ld\n", (long)delay); @@ -396,8 +368,8 @@ static void ccid3_hc_tx_packet_recv(struct sock *sk, struct sk_buff *skb) /* * Update allowed sending rate X as per draft rfc3448bis-00, 4.2/3 */ - if (hctx->state == TFRC_SSTATE_NO_FBACK) { - ccid3_hc_tx_set_state(sk, TFRC_SSTATE_FBACK); + if (!hctx->feedback) { + hctx->feedback = true; if (hctx->t_rto == 0) { /* @@ -502,7 +474,6 @@ static int ccid3_hc_tx_init(struct ccid *ccid, struct sock *sk) { struct ccid3_hc_tx_sock *hctx = ccid_priv(ccid); - hctx->state = TFRC_SSTATE_NO_SENT; hctx->hist = NULL; setup_timer(&hctx->no_feedback_timer, ccid3_hc_tx_no_feedback_timer, (unsigned long)sk); diff --git a/net/dccp/ccids/ccid3.h b/net/dccp/ccids/ccid3.h index 7884159937aa..1773a8dd36d8 100644 --- a/net/dccp/ccids/ccid3.h +++ b/net/dccp/ccids/ccid3.h @@ -70,13 +70,6 @@ enum ccid3_options { TFRC_OPT_RECEIVE_RATE = 194, }; -/* TFRC sender states */ -enum ccid3_hc_tx_states { - TFRC_SSTATE_NO_SENT = 1, - TFRC_SSTATE_NO_FBACK, - TFRC_SSTATE_FBACK, -}; - /** struct ccid3_hc_tx_sock - CCID3 sender half-connection socket * * @x - Current sending rate in 64 * bytes per second @@ -87,7 +80,7 @@ enum ccid3_hc_tx_states { * @s - Packet size in bytes * @t_rto - Nofeedback Timer setting in usecs * @t_ipi - Interpacket (send) interval (RFC 3448, 4.6) in usecs - * @state - Sender state, one of %ccid3_hc_tx_states + * @feedback - Whether feedback has been received or not * @last_win_count - Last window counter sent * @t_last_win_count - Timestamp of earliest packet with * last_win_count value sent @@ -105,7 +98,7 @@ struct ccid3_hc_tx_sock { u32 t_rto; u32 t_ipi; u16 s; - enum ccid3_hc_tx_states state:8; + bool feedback:1; u8 last_win_count; ktime_t t_last_win_count; struct timer_list no_feedback_timer; -- cgit v1.2.3